Currently, pseudo white LEDs (light-emitting diodes) are generally used as light sources for backlighting a liquid crystal display device. In a pseudo white LED, an LED which emits blue light and a yellow phosphor which emits yellow light by being excited by the blue light are used in combination, whereby white light emission is achieved (and hence they may be called blue-yellow type pseudo white LEDs). Pseudo white LEDs excel in terms of emission efficiency and cost.
Patent Document 1 proposes a technique for attaining brighter displaying in a liquid crystal display device including pseudo white LEDs. Patent Document 1 states that combining pseudo white LEDs having a predetermined emission spectrum and color filters of predetermined spectral transmission characteristics allows the lightness in the white displaying state to be enhanced without altering the chromaticity coordinates of the white displaying state.